Histology and Immunohistochemistry The Histology and Immunohistochemistry Resource is crucial for providing the prerequisite morphologic data on any sample of organ or tissue, prior to the use of the excised tissue in different analytical assays. Histological examination of tissue thus establishes the absence of abnormal pathology, such as inflammation, necrosis, hemorrhage or tumor, prior to using the extracts of the tissue in various experiments. Scientific investigation of the role of particular genes in cancer is very often dependent on the ability to translate observations obtained from methods such as enzyme linked immunosorbent assays, polymerase chain reaction or even Northern, Southern, Western blots, into identifying the cell types of expression in tissue sections. The analysis of single cells by flow cytometry, or the analysis of tissue sections with confocal microscopy is facilitated by the use of confirmatory histological methods. Very often, it is the expression of gene products in a particular tissue that allows the investigator to deduce the significance of its presence to its function. The results obtained from analysis of tissue are also critical in the planning of future directions of projects. The minimal recharge rates of this popular resource also permits Cancer Center members to examine tissues obtained from various mouse models of cancer. Although mouse histopathology is similar to human histopathology, there are numerous differences, which can confound accurate interpretation. Thus the readily available dne-on-one consultation with the resource leader, a board certified pathologist, experienced with interpretation of mouse models of human disease, is a critical asset of this resource.